So far, to eliminate a vibration, a sheet-like damping material mainly made of asphalt was attached to a floor portion of a vehicle or the like. However, in case such a sheet-like damping material is used in a vehicle or the like, it needs to cut off along the shape of a portion that is set at each vehicle. Furthermore, as it needs to set such a sheet-like damping material by workers, it interferes with an automated construction and prevented reduction of the process time. Therefore, as shown in a patent publication No. 1, it has invented a damping material (a water damping emulsion) that enables an automated construction by a robot.
In a patent publication No. 1, there is described an invention of a water damping emulsion that a solidification rate is controlled in a fixed range when drying a thick coated film that is coated over for a damping material. This is so as to prevent swellings or cracks on a coated film when moisture of inside the coated film is evaporated drying from the surface and strengthening it and to improve a drying property of a coated film that is formed for a damping material.
According to the previous invention, a water damping emulsion enables an automated construction by a painting robot. As it is water paint, it is possible not only to shorten process time but also to obtain following merits that it does not emit a smell of asphalt in the former sheet-like damping material and does not emit a smell of organic solvent coatings under the construction as well. However, in case a vehicle floor or the like applying such a water paint according to the previous invention is left at less than 20° C. low temperature, there took place a problem that generated splits or cracks on a coated film since it was bad in its film forming property at low temperature.
Therefore, in a patent publication No. 2, there is described an invention of a water damping material that is added to compatibility adjuster like various solvents, a rosin ester, a phenol resin and so on to improve a film forming property at low temperature.
Patent Application No. 1: Pat. Appln. 2004-115665
Patent Application No. 2: Pat. Appln. 2001-152028